Belt and method of marking

ABSTRACT

A method of marking a belt comprising the steps of selecting a first thermoplastic layer that is optically distinguishable from a belt body, joining the first thermoplastic layer to the belt body, joining a second thermoplastic material layer to the first thermoplastic layer, etching the first thermoplastic layer in order to contrast the first thermoplastic layer with the belt body, and etching the second thermoplastic layer in order to contrast the second thermoplastic layer with the first thermoplastic layer.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims priority from U.S.non-provisional application No. Ser. No. 10/601,263 filed Jun. 20, 2003.

FIELD OF THE INVENTION

The invention relates to a belt and method of marking a belt and moreparticularly, to a belt and method of marking a belt using at least oneoptically distinguishable polyethylene layer.

BACKGROUND OF THE INVENTION

Belts may be manufactured with or without marking indicia. Markingindicia may comprise labels, text or other material impressed or printeddirectly on the belt or a combination of the foregoing.

More particularly, the prior art teaches use of a non-vulcanized coloredrubber which is adhered to a base material. During vulcanization thecolored rubber is imprinted upon the underlying material. This oftenresults in distorted markings or undesirable surface features, such asdips of bumps. Such dips or bumps can cause noise during operation ofthe belt. It is also known that a laser may be used to apply a mark to abelt by burning or etching a mark in a product surface.

Representative of the art is Japanese Patent No. 3126937 which disclosesa method for marking a belt. What is needed is a belt and a method ofmarking a belt using a polyethylene layer that is opticallydistinguishable from a belt body. What is needed is a belt and a methodof marking a belt using an optically distinguishable polyethylene layeretched by a laser light. The present invention meets these needs.

SUMMARY OF THE INVENTION

The primary aspect of the present invention is to provide a belt and amethod of marking a belt using a polyethylene layer that is opticallydistinguishable from a belt body.

Another aspect of the invention is to provide a belt and a method ofmarking a belt using an optically distinguishable polyethylene layeretched by laser light.

Other aspects of the invention will be pointed out or made apparent bythe following description of the invention and the accompanyingdrawings.

The invention comprises a method of marking a belt comprising the stepsof selecting a first thermoplastic layer that is opticallydistinguishable from a belt body, joining the first thermoplastic layerto the belt body, joining a second thermoplastic material layer to thefirst thermoplastic layer, etching the first thermoplastic layer inorder to contrast the first thermoplastic layer with the belt body, andetching the second thermoplastic layer in order to contrast the secondthermoplastic layer with the first thermoplastic layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional perspective view of a belt having anoptically distinguishable polyethylene layer.

FIG. 2 is a perspective view of a belt having an opticallydistinguishable layer etched by laser light.

FIG. 3 is a cross-sectional view of a multi-ribbed profile.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a cross sectional perspective view of a belt having anoptically distinguishable polyethylene (PE) layer. The illustrativeproduct comprises a power transmission belt 100 used, for example, in anautomotive or industrial application.

Belt 100 comprises an elastomeric body 10 with tensile members 20embedded therein. The tensile members 20 extend parallel to alongitudinal axis. Tensile members 20 may comprise any material known inthe belt art, including polyester, nylon, aramid and their equivalents.Tensile members 20 extend longitudinally within the body 10.

A profile comprising transverse teeth or cogs 11 extend transverse toand along a longitudinal surface of the belt body 10. The profile mayalso comprise a multi-ribbed surface, see FIG. 3.

Layer 30 comprises a thermoplastic material. Thermoplastic layer 30 isjoined to body 10 by use of any suitable cure, chemical adhesive ormolding process known in the art. Although the preferred embodiment usesa peroxide cure process, thermoplastic layer 30 may also be joined tobody 10 using chemical adhesives known in the art and by molding.

Body 10 may comprise thermoset elastomeric material such as hydrogenatednitrile butadiene rubber (HNBR), ethylene-propylene (diene) rubber(EPDM), styrene-butadiene rubber (SBR), chloroprene rubber (CR), naturalrubber (NR), nitrile rubber (NBR), butyl rubber (BR) or any otherelastomeric materials used in power transmission belts.

Layer 30 is selected with beneficial characteristics to create anoptical appearance or contrast that is distinguishable from a belt body10 or adjacent layer. Optical as used herein refers to visual andnon-visual electromagnetic (EM) radiation. Layer 30 has a thickness inthe range of approximately 3.5 mils to 30 mils.

The characteristics of the layer may include a particular color,texture, or reflectivity that optically distinguishes layer 30 from beltbody 10. The difference in appearance, or contrast, results fromdifferences in reflected electromagnetic (EM) radiation so that thelayer 30 can be distinguished from belt body 10 by a person's eye(visually), with an optical scanner such as a bar code reader, or by anyother scanner or means of detecting visual or non-visual EM radiation.Layer 30 may also comprise any visually detectable color or combinationof colors. In the instant embodiment layer 30 comprises polyethylene(PE) having a particular distinguishing characteristic, that is, color,preferable other that black. By way of example and not of limitation,layer 30 may also substantially comprise polypropylene, polyester,polyamide, polyvinylidene chloride, polyvinyl chloride and anyequivalents or combinations thereof. Each of the foregoing beingoptically distinguishable. In the case of polyethylene, layer 30 iscompatible with and co-curable with ethylene propylene rubbers viaperoxide cure.

Use of polyethylene has the advantage of avoiding the need for aseparate rubber mixing step as is the case with prior art colored rubberstocks. The PE sheet material has additional advantages includingavailability in a wide range of thicknesses, relatively low costcompared to mixing rubber stocks, ease of storage and processing, and itis readily recyclable.

FIG. 2 is a perspective view of a belt having an opticallydistinguishable layer etched by laser light. In this embodiment layer 40is molded, joined or cured to the belt body 10 under layer 30. Layer 40has a thickness in the range of approximately 3.5 mils to 30 mils.

Once the belt is cured or molded, a laser light 60 from a laser lightsource 61 is focused upon a selected portion of layer 30. The intensityand position of the laser light source 61, and thereby the laser light60, is adjusted and moved in order to remove selected portions of layer30 without damaging underlying layer 40, thereby exposing a portion oflayer 40. The intensity of the laser light 60 may be adjusted in orderto penetrate any thickness of layer 30. Since layer 30 is opticallydistinguishable from layer 40, the removed portions of layer 30 exposelayer 40, which then comprise a detectable mark on the belt. As anexample, mark 50 depicts the number “20”. Of course, any symbol, text,or other desired pattern can be etched into layer 30 to serve as a markon the belt or product.

Layer 30 may also be etched to mark a belt in the absence of layer 40.In this embodiment, belt body 10 provides a particular opticalappearance and contrast to distinguish it compared to layer 30. Theoptical appearance of layer 30 is properly selected to distinguish itfrom the optical appearance of belt body 10.

In another embodiment, prior to cure layer 30 has selected portionsremoved, for example by etching, cutting or grinding prior to assemblingand curing the belt. Cuts in layer 30 depict the same mark as describedin FIG. 2, only the cuts used to make mark 50 are not performed usinglaser light. They may be ground or die cut into layer 30 using toolsknown in the art. The layer would then be cured or molded with theproduct as otherwise described herein, rendering a permanent marking ofthe belt or product.

In yet another embodiment a plurality of optically distinguishablelayers are ‘stacked’ or layered together on a belt. Each layer has anappearance which contrasts with or distinguishes it from each of theother layers. A laser light is then selectively operated at differentintensities and positions in order to remove selective portions ofoverlying layers to expose different portions of particular underlyinglayers. In this manner a variable appearance is etched into the belt orother product. This may include different colors and layers beingexposed to indicate different information about the belt, for example,part or inventory numbers. It may also be used to create a visuallyappealing effect on a belt or product using different colors andpatterns. Although FIG. 2 depicts two layers as an example and not as alimitation, any number of layers may be stacked to achieve the describedeffect.

In yet another embodiment a plurality of optically distinguishablelayers are ‘stacked’ or layered together on a product as describedpreviously. Each layer has a different appearance to distinguish it fromeach of the other layers. In this embodiment a knife, grinder, cuttingtool, or die cutter is used to remove portions of overlying orunderlying layers to selectively expose different portions of particularlayers. In this manner a variable appearance may be realized on the beltor product. As described herein, this may include different colors andlayers being exposed to illustrate different information about the beltor product. It may also be used to create a visually appealing effect ona belt or product using different colors. Although FIG. 2 depicts twolayers as an example, any number of layers may be stacked to achieve thedescribed effect.

In yet another embodiment, separate regions having different colors maybe formed in each layer 30 and layer 40. The different color regions ineach layer may be disposed laterally adjacent to each other across asurface of layer 30 or layer 40. They may also have any form as may berequired to achieve a desired visual effect.

For example, referring to FIG. 3, regions 31, 42 may be blue, whileregions 32, 41 may be green and so on, each region being adjacent toeach other and disposed parallel to a belt length. Each region beingoptically distinguishable from all other adjacent regions bothvertically and laterally. Each region is then etched in order to exposediffering portions of each adjacent region. This affords yet anothermeans of making unique markings on a belt or product.

FIG. 3 is a cross-sectional view of a multi-ribbed profile. A profilecomprising ribs 110 extend along a longitudinal axis of a belt. Regions31, 32, 41, 42 of layer 30 and layer 40 each have having differingoptical appearances are depicted.

Although forms of the invention have been described herein, it will beobvious to those skilled in the art that other variations may be made inthe construction and relation of parts without departing from the spiritand scope of the invention described herein.

1. A method of marking a belt comprising the steps of: selecting a firstthermoplastic layer that is optically distinguishable from a belt body;joining the first thermoplastic layer to the belt body; joining a secondthermoplastic material layer to the first thermoplastic layer; etchingthe first thermoplastic layer in order to contrast the firstthermoplastic layer with the belt body; and etching the secondthermoplastic layer in order to contrast the second thermoplastic layerwith the first thermoplastic layer.
 2. The method as in claim 1, whereinetching comprises cutting a pattern into the first thermoplastic layer.3. The method as in claim 1, wherein etching comprises cutting a patterninto the second thermoplastic layer.
 4. The method as in claim 2,wherein etching comprises using a laser light.
 5. The method as in claim3, wherein etching comprises using a laser light.